Vacuum chambers are well known and are employed in the semiconductor industry to etch and deposit thin films and form contacts in semiconductor substrates during manufacture of, inter alia, integrated circuits. State-of-the art processing chambers form a part of a system able to condition and preclean substrates for vacuum processing and process them without leaving a vacuum environment.
However, a substrate preclean step, while it is effective in removing material adhered to the surface of the substrate, distributes this :material on other surfaces within the vacuum chamber, e.g., on the walls or shields, lid and door of the chamber. In time there is a build up of this material that causes flakes to form on these surfaces that can deposit onto the substrate surface. At that point the chamber must be disassembled for cleaning.
The present lid for a vacuum etch chamber comprises a two-piece aluminum lid separated by an RF gasket, which is a low resistance contact for the 60 MHz RF power supply for the vacuum chamber. Two aluminum plates are screwed together by a plurality of screws that fasten the two plates together so they make good contact to the RF gasket therebetween. As material builds up on the lid however, as described hereinabove, it must be periodically cleaned to remove the built up material. This is generally done by a wet chemical cleaning process which requires that the lid be disassembled, the screws removed, the lid cleaned and then the lid be re-assembled. However, the act of assembly, e.g., inserting and fastening the screws, itself creates particles, so that the chamber is not clean, i.e., free of particles, even after the cleaning step. Other parts of the vacuum chamber, such as the door for the lid and a shield around the substrate support that prevents material from depositing on the walls of the chamber, must also be periodically cleaned; this adds to the downtime of the equipment and consequently increases costs of manufacture.
Thus it would be desirable to have a vacuum chamber lid that does not have to be disassembled and assembled again for cleaning; further it would be desirable to pre-treat replaceable parts for a vacuum chamber so that particles generated in the vacuum chamber that adhere to the lid, door and shield surfaces have improved adherence to these surfaces with the result that the time between cleaning cycles can be extended, thereby reducing downtime of the equipment.